Campaigners have called on the government to maintain the European Commission's ban on neonicotinoids, following new evidence of links between the insecticides and bee decline.
Research led by the Centre for Ecology and Hydrology examined changes in 62 wild bee species across oilseed rape cropping patterns in England between 1994 and 2011 – the years spanning the wide-scale commercial use of neonicotinoids.
It concluded that use of the insecticide was to blame for large-scale and long-term decline in wild bee species. The decrease was three times higher among species that regularly feed on oilseed rape, including the buff-tailed bumblebee, compared to bees that forage on a range of floral resources, the study revealed.
For five species of wild bees, researchers found neonicotinoids were to blame for the extinction of at least 20% of the local population.
Lead author, Dr Ben Woodcock, said: ‘As a flowering crop, oilseed rape is beneficial for pollinating insects. This benefit however, appears to be more than nullified by the effect of neonicotinoid seed treatment on a range of wild bee species.’
Habitat loss and fragmentation, pathogens, climate change and other insecticides were also contributing to bee decline, he added.
The results of the study will feed into a review of the risks of neonicotinoid pesticides being undertaken by the European Food Standards Authority (Efsa). This is expected to be complete by January 2017. A review by the agency in 2013 led to a ban on Syngenta’s thiamethoxam and Bayers’ clothiandin and imidacloprid across member states.
However, the UK government opposed the ban and, in summer 2013, approved an application by the National Farmers Union (NFU) to use the restricted insecticides on a limited area of oilseed rape.
Earlier this year, the government rejected an application to treat a larger area of crops after its Expert Committee on Pesticides ruled that the NFU’s submission lacked evidence. But campaigners remain fearful that, once the UK leaves the EU, authorities will drop the ban under pressure from the farming lobby.
Liberal Democrat MEP Catherine Bearder said: ‘The government must give guarantees that the current EU ban on these harmful pesticides will remain in place after Brexit.
‘Wild bees play a vital role in our ecosystem and UK farming, protecting them means ensuring our food security,’ she added.
Friends of the Earth nature campaigner Paul de Zylva said that the findings of the study by the Centre for Ecology and Hydrology were the strongest evidence yet of the harm neonicotinoids pose to bees in the UK.
‘If the government genuinely wants to safeguard Britain’s bees, it must keep the ban on neonicotinoid pesticides regardless of what happens with Brexit, and tighten the way pesticides are tested and licensed for use,’ he said.
